NEW FILLING METHOD FOR THROUGH HOLE

摘要

PROBLEM TO BE SOLVED: To provide a method in which an opening in a substrate such as a through hole or the like is filled. SOLUTION: An epoxy resin-based dielectric film 16 which covers an opening 14 is arranged on a substrate 12 which comprises the opening 14. The dielectric film 16 is made to reflow so as to flow into the opening 14. A continuous dielectric which is extended into the opening 14 from the dielectric film 16 is formed. When a via 18 is formed after the opening 14 is filled, light is image-formed on the dielectric film 16, the via 18 is metallized, and a circuit structure 24 is formed. It is preferable that the dielectric film 16 contains 0 to 50% of inorganic fine particles, 50 to 100% of an epoxy resin and a cation photoinhibitor of 0.1 to 15 pts.wt. in terms of the total weight of the resin are contained.